Not just any potting soil will do

A well-blended potting mix is one of the most important secrets to healthy plant perfor- mance.

I once purchased a generic potting mix that was inexpensive. I thought I was getting a great deal; however, I soon found out that it contained nothing to help retain moisture. In order to make the potting soil suitable for my plants I needed to add amendments.

When purchasing a ready-made potting mix, read the labels to ensure it has the following amendments, or simply make your own potting mix:

Perlite: The white puffy material in potting mixes that looks like Styrofoam balls is generally perlite, although some mixes actually use Styrofoam. Whatever the makeup, these white balls provide air space in the potting medium.

Perlite is a volcanic rock that has been heated and then "popped" like popcorn. It contains numerous pores that help water drain though the potting mix quickly. Perlite particles create tiny air tunnels, which allow moisture and oxygen to flow freely to the roots.

Some plants purchased at the nursery have a substantial amount of perlite in the container. The reason for this is that perlite is lighter than soil; therefore, it saves costs in shipping.

Vermiculite: Vermiculite, which generally has a shiny, golden appearance, comes from the mineral mica. Like perlite, the mica has been heated until it expands, which is why vermiculite also helps hold water in a potting medium.

Vermiculite comes in different grades. One grade is used for insulation; others are for horticulture purposes.

Peat moss: Peat retains moisture and releases water slowly as plants need it. Peat moss allows for proper root growth by loosening and aerating soils. It protects soils from hardening and adds organic material.

You can bind sandy soil by adding body to the sandy soil using peat moss. This regulates moisture and air around the plant roots for ideal growing conditions.

The most common ingredient in potting mixes, peat moss is made up of partially decomposed plants harvested from peat bogs. It absorbs water (some types up to 10 times their weight), yet it provides air space so roots do not suffocate.

Sand: Horticulture sand is composed of tiny pieces of rock. Just like sandy soil outside, sand improves drainage. Plants that do well in a potting medium that contains a large amount of sand include cacti and succu- lents.

One of the worse things to do is to attempt to use your heavy garden soil in a container for plants. The average garden soil in a container will actually choke the roots of your plants. It does not allow air to flow freely around the roots, nor does it supply sufficient drainage.

Bark: Some potting mixes, especially those for epiphytes (plants that do not need soil) such as some orchids and ferns, contain composted bark. It is excellent at increasing drainage, yet holds few nutrients.

Uses for perlite and peat moss

Some container plants you have outdoors may do well indoors also. Some examples are geraniums, azaleas, kalanchoe, star pine, jungle geraniums, bromeliads, wax begonias, maiden hair fern and kangaroo vine.

During the hot summer, bring them indoors and place in a sunny location. Do not place next to a window where it can get heat damage. Set trays of water in the plant area and add perlite.

Set the plants on the perlite and keep moist all times. The water will slowly be released into the atmosphere, benefiting the plant. Misting plants often will also help, as well as using a peat moss base planting medium with perlite, to help these humidity-loving plants survive our heat.

Never add so much water to the tray of perlite that the bottom of the plant container is sitting in the water, as this will rot the roots of the plant. Add just enough to keep the perlite moist to add humidity around the plants. If you are an orchid grower, this method is excellent to add the much-needed humidity orchids require.

To create an eye-catching basket display, purchase a wire basket, plastic lining, peat-based potting mixture and sphagnum moss.

Line the basket with a two-inch layer of damp moss. Place the plastic over this and make small holes around the base of the plastic.

Water the plants you have chosen to group in your basket, remove from the pots and divide into smaller sections you can push through the moss and holes in the plastic. When choosing your plant grouping, read the labels to make sure all plants have the same light and water requirements for better success.

Next take your sections and push through the hole in the plastic, flower side first; the root side will be inside the basket while your plant will be hanging down between the wires out the basket.

Complete planting around the base, then cover with another layer of peat-based potting mixture. Finish planting the sides and top of basket.

When the basket is full, tuck in excess plastic. Water well and secure for hanging in a partial sunny place and enjoy your basket full of color!

Watering plants

Frequency of watering depends on the type of plant and size. Most plants prefer the growing media to be "just moist" at all times.

Some plants like the jade plant and large leafed ficus like to become almost dry before water is applied. Do not let the growing medium to become so dry that space forms between it and the container. When this happens, water rushes down the inside of the pot rather than wetting the root zone.

For your information: African violets add lovely color to your home. When the roots fill the pot you bought it in, repot with a mixture of peat moss, perlite and vermiculite. When watering avoid getting the leaves wet, as this will cause the leaves to rot.

It is best to water African violets from below by filling the drip saucer with water. Allow the plant to soak up what it needs; once the surface is moist discard any water left in the saucer. Do not water again until the soil is almost dry.

Debi Papp, a member of the Yuma Garden Club and various other gardening organizations, can be contacted at 783-3189 or at greenthumbs1@adelphia.net.